This error typically occurs when the Kepware installer cannot verify the digital signatures of its own installation files because the host operating system is missing essential root certificates. This is common on systems that are offline or have not received recent Windows Updates. Quick Fixes
If you want, I can draft a PowerShell script to (1) check for presence of common root CAs, (2) test connectivity to common CRL/OCSP endpoints, and (3) import a provided root certificate into the Local Machine Trusted Root store. This error typically occurs when the Kepware installer
Summary
If the error persists after these steps, check the installation logs located at C:\Program Files (x86)\Kepware\KEPServerEX\bootstrap.log for specific certificate thumbprints that are failing. You may also find detailed guidance on the PTC Support Portal regarding this specific installer failure. The Installer was unable to find required root certificates Kepware: "The installer was unable to find required